Brown discharge after ultrasound : due May 21

Hi Girls, I am due May 21 I had my first ultrasound last Wednesday and have had brown watery discharge since. Not too much just when I wipe and am nervous. I have had 1 previous miscarriage. My bloodwork was good last week and ultrasound was normal for 5 weeks 5 days. 
Should I be concerned ? I am nervous to workout or do to much.